Fonte:
http://www.dgaiec.min-financas.pt/NR/rdonlyres/7184D26C-EC7F-4BEB-BE2F-E1B2E4FB9E37/0/Circular_n_02_2010_II.pdf
http://www.dgaiec.min-financas.pt/NR/rdonlyres/E3A0AA4B-FB32-4047-A297-E2E13AAFB543/0/Circular_n_3_2010_II.pdf
